JPS6247174A - Manufacture of semiconductor light emitting device - Google Patents

Abstract

PURPOSE:To stably manufacture a semiconductor device which emits & blue light in a mass production by forming a P-N junction of N-type and P-type ZnSyse1-y formed by a prescribed method. CONSTITUTION:After a mixture which contains excess (1.05-1.2 equivalent ratio) of low boiling point component of R1Zn and R2Se (where R is alkyl group of CH3, etc.) is thermally reacted at 0-40 deg.C for 10-180 min, matured at 30-80 deg.C for 10-120min, excess component is distilled, and removed to obtain an organic zinc compound as a zinc source. A P-N junction of ZnSySe1-y (0<=y<=1) is formed on a substrate made of GaAs by an MOSCVD method by organic compound which contains organic zinc compound, organic metal compound containing III group element as an N-type III group dopant or halogen element, carrier gas, hydrogen sulfide, hydrogen selenide, ammonia to become a P-type dopant, hydrogen phosphate, or hydrogen arsenide. Thus, a semiconductor device which emits a blue light can be manufactured in a mass production.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for manufacturing a semiconductor light emitting device H that emits blue light.

[Summary of the invention]

The present invention provides a method for manufacturing a semiconductor light emitting device that emits blue light using a P-n junction formed by n-type ZnSySe1-y (0≦y≦1) and P-type ZnSySe1-y (0≦y≦1). An adduct of dialkylzinc and dialkylselenium obtained by mixing dialkylzinc and dialkylselenium in an almost excessive amount of the lower boiling point component of both, reacting and aging by heating, and then removing the excess component by distillation. The above-mentioned n
By forming a - type or P- type Zn5ySθ1-y layer, it is possible to mass-produce semiconductor devices 1a that emit blue light.

[Conventional technology]

An outline of semiconductor light emitting devices that emit blue light that have been reported or put into practical use will be described below.

1. A light emitting device having a P-n junction formed by diffusing a dopant into a bulk ZnSθ single crystal. (For example, J,
Appl, Phys, 57, (1985)
2210, Published Patent Publication 1983-6583 Reference 2
, a light emitting device L having a P-n junction formed by diffusing a dopant into a bulk Zn5ySθ1-y single crystal (for example, Appl, Phys, Lett, 27 (
1975) 74, see) 5. A light emitting device having an M-S structure in which an insulating layer and an electrode layer are laminated on a bulk n-type Zn5ySθ1-y single crystal. (e.g., Apl)l, Phys,'Lθtt,, 27
(1975) 697, Japan, J. Appl.
, Phys., 15 (1974) 357,
Japan, J., Appl., Phys., 16 (
1977) 77, 4. M with an insulating layer and an electrode layer stacked on n-type GaN
A light-emitting device having an S structure. (For example, see Nikkei Electronics, May 11, 1981, p. 82.) 5. A light emitting device using a P-n junction of SiO.

(For example, [] Kei Electronics May 1979 2
8th issue F, 111) [Object to be solved by the invention] The above-mentioned prior art has the following problems.

B. Prior art 1 and 2... Since bulk crystals, which are currently considered extremely difficult to enlarge, are used as the starting material, and the dopant diffusion process is performed in a batch process in a closed system, IA Productivity and process reproducibility are poor.

1. Prior Art 5 and 4... The light emitting device has an M engineering St # structure, and light emission occurs due to recombination of minority gears injected through an insulating layer.
Compared to prior art techniques 1 and 2 in which light is emitted by recombining majority carriers in the vicinity of the P-n junction surface, the luminous efficiency is theoretically lower.

C. Prior art 5... Since sio is an indirect transition type semiconductor, the improvement in luminous efficiency is small from M1 to S10. Sex is also lacking.

Therefore, the present invention aims to solve the above-mentioned problems in the prior art, and its purpose is to use ZnSySe, a direct transition semiconductor that can be expected to have high luminous efficiency.
Using 1-y, a semiconductor light emitting device having a P-n junction can be fabricated using GaAs, G
It is fabricated on aP, Si, etc. by the MOCVD method using an organozinc compound, which is an adduct of dialkylzinc and dialkylselenium, as a zinc source, which is excellent in productivity and controllability of crystal growth, and provides a high-quality epitaxial film. The company produces semiconductor light emitting devices that emit blue light.

[Means for solving problems]

In the method for manufacturing a semiconductor light emitting device according to the present invention, n-type ZnSySe1-y (0≦y≦1) and P-type ZnSy
P − formed by Se1-y, (0≦y≦1)
When manufacturing a semiconductor light-emitting device that emits blue light using an n-junction, dialkylzinc and dialkylselenium are mixed in an approximately excessive amount of the low boiling point component of both, and after reacting and aging by heating, the excess is mixed. The n-type or P-
It is characterized by forming a type Zn5ySθ1-7 layer [
Examples] A method for producing an organic zinc compound comprising an adduct used in the present invention will be described.

Dialkylzinc (RZn) and dialkylselenium (R
2Se) is obtained as a result of a one-to-one acid-base reaction between R2Zn as an electron acceptor and R2Se as an electron donor, and has the structure R2Zn-3eRz. The following steps are required to produce the adduct.

Rs Zn and R2Be are mixed with the low boiling point component being in excess of both, preferably at a ratio of low boiling point component to high boiling point component of 1.05 to 1.2. The reaction is carried out at a temperature below the boiling point, approximately 0°C to 40°C for 10 minutes to 3 hours, preferably 10 to 35°C for 30 minutes to 1 hour.

After that, in order to complete the reaction, the temperature was gradually increased to 30 to 8
Aging is performed at 0° C. for 10 minutes to 2 hours, preferably 10 to 30 minutes to 1 hour.

Finally, excess components are removed by distillation.

The formation of adducts can be confirmed by the following facts.

(1) Heat is generated by mixing the two.

(2) The vapor pressure-temperature curve of the adduct produced is different from that of both the starting materials R2Zn and R2Be.

(8) The remaining amount after subtracting the distilled excess component from the raw material mixture corresponds to the weight M assuming that R2Z n and R2S form an adduct at a ratio of 1:1.

As a specific example, (oHa)gZn and (oHs)2
adduct consisting of s8 (OH3)2zn-8s(oHa
) 2 will be explained.

Add (OH3)zse to a 300d round bottom flask at 63%.
Charge 5f (0.58S mol) and add (OH
3) 2Zn5a5r (0,613 mol) E was added dropwise to react. The reaction was exothermic and generated a large amount of heat.

The reaction temperature was controlled at 8 to 15°C, and the reaction was carried out for 40 minutes. After that, the temperature was gradually increased at a rate of 15℃/hour, and at 45℃
Time aged. Thereafter, unnecessary excess content was removed by distillation. The product is 118? Met.

FIG. 1 shows the vapor pressure-temperature characteristics of the obtained adduct, where the horizontal axis 1 is the temperature and the vertical axis 2 is the vapor pressure.

The solid line 3 is the adduct, and the broken line 4.5 is the raw material.
The vapor pressure characteristics of e(OHa)z and (OH3)2Zn are shown.

Table 1 also shows the vapor pressure values at typical temperatures.

(Table 1) Further, the adducts shown in Table 2 were obtained by going through the same steps.

An example of manufacturing a semiconductor light emitting device by the MOOVD method using an adduct formed by the above manufacturing method will be shown below.

FIG. 2 is a schematic diagram of the MOOVD apparatus used in the present invention.

A graphite susceptor 7 coated with SiO is placed inside the horizontal reaction tube B made of quartz glass, and a high frequency heating furnace and an infrared furnace are connected from the side of the reactor, on which a substrate 8 is placed. Alternatively, the substrate is heated using a resistance heating furnace 9 or the like. The substrate temperature is monitored by a thermocouple 10 embedded in a graphite susceptor 7. The reaction tube is connected to an exhaust system 11 and a waste gas treatment system 12 via valves 13,14. The adduct, which is a Zn source, is enclosed in a bubbler 15.

An organometallic compound containing a group Ⅰ element or an organic compound containing a halogen element serving as a source of an n-type dopant is enclosed in a bubbler 16 . Carrier gas, selenium, hydrogen selenide (Hasθ), and hydrogen sulfide (His) are filled in cylinders 17, 18, and 24, respectively. The flow rate of the carrier gas, hydrogen selenide, and hydrogen sulfide purified by the purification device 19 is controlled by a mass 70-controller 2o. Bubbler 15.1 (the adduct sealed in S and the n-type dopant are kept at a predetermined temperature IQ in a constant temperature bath 21)
: Maintained. A desired amount of adduct and n-type dopant are supplied by introducing an appropriate amount of carrier gas into the bubbler and performing bubbling. cylinder 2
5 contains a gas such as chlorine, hydrogen chloride, hydrogen bromide, hydrogen iodide, etc., which becomes an n-type dopant, and the cylinder 26 contains P.
Gases such as ammonia, hydrogen phosphide, and hydrogen arsenide, which serve as - type dopants, are filled in a diluted state with hydrogen gas. The flow rate of the dopant gas is controlled by the mass 70-controller 20. The adduct, selenium hydrogen, hydrogen sulfide, and dopant supplied in the manner described above are each diluted with a carrier gas, then merged and introduced into the reaction tube 6 via the three-way pulp 22. Mikata pulp 22
switches between introducing the raw material gas into the reaction tube 6 and disposing it into the waste gas treatment system 12. Although FIG. 2 shows a horizontal reactor, the basic configuration is the same for a vertical reactor.

However, it is necessary to ensure the uniformity of the film obtained by providing a rotation mechanism for the substrate.

Epitaxial growth of ZnSySe1-y (0≦y≦1) on the substrate is performed as follows. The cleaned and etched substrate is placed in a reactor. Thereafter, the inside of the reactor is evacuated to about 10-' Torr to remove any gas remaining in the system. After introducing a carrier gas and returning the inside of the system to normal pressure, temperature increase is started while flowing carrier gas of about 1 to 2 t/-. Hydrogen or helium was used as the carrier gas. After the substrate temperature reaches the predetermined temperature and stabilizes, supply of raw material gas is started and Zn5ySθ
! -Grow y. After growing for a specified period of time,
Stop supply of raw materials and cool. During cooling, He or H2 is allowed to flow for 1 to 217 m. Add 30 to 60 ml of hydrogen selenide or hydrogen sulfide to prevent thermal etching of the substrate surface.
It may be cooled with a flow of about /-. When the substrate returns to room temperature, the reactor is evacuated to remove hydrogen sulfide remaining in the system. After returning the pressure inside the system to atmospheric pressure, the substrate is taken out.

By performing crystal growth according to the above-mentioned steps using the MOOVD apparatus shown in FIG. 2, n-type ZnSySe
1-7. A P-type ZnSySe1-y epitaxial film can be formed.

[Example 1] Production of a semiconductor light emitting device having a Zn5eP-n junction (ioo) of n-type gallium arsenide (GaAs), (
1oo) 5° or 2° in the direction of the (110) plane
A semiconductor light-emitting device is manufactured according to the following steps on a semiconductor light-emitting device having a deviation of .

1. Formation of n-type ZnSθ Substrate temperature: 200 to 530'C (oHs)zzn-Be(OH3)z adduct bubbling gas flow rate: At bubbler temperature -15°C, 30
-/supply of 2% Hf1E3θ diluted with rigid Hl [220Q
sj/m Bubbling gas flow rate of triethylaluminum (TEAt) 10 to 3 Q d at 8 bars and 1 temperature -10°C
/mr Total gas flow including carrier gas MS4.5t/Growth time: 2Q Qm Under the above conditions, an n-type Zn88 layer of approximately 6 μm can be epitaxially grown on GaAs.

The specific resistance of the film was approximately 0.5 to 10 Ω·m.

Formation of zp type znse After the formation of n-type Z n S e J@ is completed, the supply of reaction gas to the reactor is interrupted by operating the three-way pulp 22 . Subsequently, the supply of TEAt, which is an n-type dopant, is stopped, and the supply of NH8, which is a P-type dopant, is started. After the reaction gas is discarded for a while and the flow rate becomes stable, the three-way pulp 22 is operated again to introduce the reaction gas into the reactor. A P-type Zn88 layer is laminated on the n-type Zn5e layer.

The growth conditions are as follows.

Supply amount of 5% NH diluted with H8: 5 to 30 g/m Growth time: 200 g/m Other conditions were the same as those for forming n-type Zn5e.

At this time, a P-type Zn5e layer with a thickness of about 3 μm can be epitaxially grown. The specific resistance of the gland is approximately 10-130
It was about Ω·m.

5. Formation of ohmic contact An ohmic contact is formed under the following conditions.

GaAs substrate Au-Ge (Ge = 12 wt-%) or Au-
After evaporating 8n at about 2000X, in an inert atmosphere.
P-type ZnSθ layer A is heat-treated at ℃ for 5 to 10 days, and Au, In, Zn, etc. are evaporated to a thickness of about 100W.

Mouth, apply conductive silver paste.

C. A light-emitting device having a P-n junction formed by attaching In-Ga and In-Hg to the surface and undergoing more than 5 steps of treatment at 300 to 400°C in an inert atmosphere, with a size of about 200 μm x 200 μm. After cutting into chips, leads are taken out from the P single layer side and the GaAs substrate side, and when a forward bias is applied, blue light emission is obtained. The luminescence intensity increased with the current, and the luminance when 20 mA was applied was about 2 to 3 millicandela.

A typical emission spectrum is shown in FIG. The peak wavelength of the emission spectrum is approximately 475 to 485 nm at room temperature.
The half width was approximately j Onm. The luminescent color was pure blue to the naked eye. In this example, the following effects were obtained.

1. The variations in the emission wavelength, emission threshold voltage, and current of light-emitting devices fabricated from the same wafer were about 10% on average.

2. The variation in characteristics of light emitting devices manufactured from wafers on which p-n junctions were formed in different wafers or in different batches was about 15 to 20%.

As described above, a light emitting device with little variation can be produced in this embodiment. In this example, a light emitting device was fabricated on a wafer with a diameter of approximately 1 inch.
By changing the size and shape of the reactor, it is also possible to process a plurality of wafers with even larger diameters. Incidentally, the time required for the manufacturing process is approximately 8 hours for the ZnSθ growth process and approximately 5 hours for the subsequent process. It is obvious that the rat productivity is significantly improved compared to the conventional technology in which bulk crystals are handled in a closed system.

[Example 2] Method for manufacturing a semiconductor light emitting device having a ZnSySe1-y (0(y≦1)P-r1 junction).

n-type gallium arsenide (GaAs), gallium phosphide (G
ap), silicon (sl)s germanium (Go) (7
) A semiconductor light emitting device is fabricated on a plane having a deviation of 5° or 2° from the (100) plane or the (1oo) plane in the (110) direction according to the following steps.

1. Formation substrate of n-type ZnSySe1-y = 200
~530'Q (OH3)lZn-8e(OHM)* adduct (7
,) Huffling gas flow rate: 30 m4/m supply of 2% H2Be diluted with Hl at temperature -15 °C filt: o~20
Supply of 2% H2S diluted with 0wj/Kaku■, Asahi: 0~200-
Bubbling gas flow rate of triethylaluminum (TEAt): 10 to 5 Q y at bubbler temperature -10°C
7 m Total gas flow rate including carrier gas: 4.5 ki Growth time = 200 editions In order to change the solid phase composition ratio y of ZnSySe1-7, it is sufficient to change the composition ratio of H2S8 and H2S in the source gas. FIG. 4 shows the correlation between the gas composition and the solid phase composition ratio of ZnSySe1-y. Epitaxially grown Zn
In order to improve the crystallinity of 5ySθ1-y, it is desirable to select a solid phase composition that is lattice-matched to the substrate. Table 5 shows the types of substrates and the ZnSy that has lattice matching with the substrate used.
H2E for growing Se1-y] θ, H1! S
Shows the composition ratio.

(Table 3) Substrate (Hg S)/((Hz s)+(a2Be
)) Ge 0.6
4GaA8 0.70Ga
P 0.9551
Under the condition of 0.97 or more, n-type ZnSySe1-y f9j of about 5μ door size can be epitaxially grown. The specific resistance of the film is CtS~20
It was about Ω·m.

2. Formation of P-type Zn5e After the formation of the n-type ZnSySe1-y layer, the supply of reaction gas to the reactor is interrupted by operating the Mikata/(Luzo 22). The supply of N Hg, which is a P-type dopant, is stopped.The reaction gas is discarded for a while, and after the flow rate becomes stable, the three-way loop 22 is operated again to transfer the reaction gas to the reactor. to be introduced. P-type ZnSySe1-y layers, □, . . . , are laminated on the n-type Zn8ySel-y layer. The growth conditions are as follows.

Supply amount of 5% NH3 diluted with Hg: 5-30/Growth time: 2 Q Qm Other conditions are the same as those for forming n-type Zn5a.

At this time, a P-type Zn80 layer with a thickness of about 3 μm can be epitaxially grown. The specific resistance of the membrane is approximately 15-200Ω・m
It was about.

5. Formation of ohmic contact An ohmic contact is formed under the following conditions.

GaP substrate Au-81 (Si=2%) or Au-Sn
After about oo1 vapor deposition, 300-600℃ in an inert atmosphere,
Heat treated for 5 minutes A Si, Ge substrate At or At-81 (Si=2%) was sputtered or vapor-deposited to about 3000λ, and heated at 300℃30 in an inert atmosphere.
P-type Zn5ySal-y layer is heat-treated for 1 minute, and Au, In, Zn, etc. are deposited to a thickness of about 100X.

Mouth, apply conductive silver paste.

C. A light emitting device having a P-n junction formed by adhering In-Ga, [ln-Hg to the surface and undergoing heat treatment for about 5 or more times at 300 to 400°C in an inert atmosphere. After cutting out the chip into a chip of about 100 mA, take out the leads from the P single layer side and the GaAs substrate side and apply a forward bias. The brightness was approximately 2-2.5 millicandela.

The peak wavelength of the emission spectrum changed depending on the composition of Zn5y8el-y, and shifted to the shorter wavelength side as y increased. The same effect as in Example 1 was obtained in this example, in which the half-width was about 10%.

[Example 3] In Examples 1 and 2, TI! was used as the n-type dopant.
! Although At was used, ZnSySe1 can be easily inferred.
In the same way as the addition of At to -y, the addition of Ga and In is also possible by using the corresponding organometallic compounds, such as triethylgallium (boiling point = 145°C) and triethylindium (boiling point = 184°C). . In addition, n-type dopants include chlorine, hydrogen chloride, hydrogen bromide, hydrogen iodide, and organic compounds containing halogen elements, such as 1°4-dichlorobutane, tetravir bromide, methylene difluoride, etc. n-type Zn BySol- which can be used and uses a halogen element as a donor in the same manner as in the above embodiments.
y can be formed.

In addition to NHa, P-type dopants include PHa.
AsH2 or the like can be used.

The light emitting device manufactured using the above-described dopant exhibited characteristics similar to those obtained in Example 1 or 2 when the doping amount was comparable to that of Examples 1 and 2.

Furthermore, regarding the adduct as a zinc source, Example 1
．． In addition to (OH8)2Zn-Be(OHI)2 used in 2, three types of adducts listed in Table 2 can be used.

The amount of adduct supplied is given under the bubbling conditions in Examples 1 and 2 (OHs)zZn-se(oHs)z
When the supply amount of ZnBe and Zn5ySsl-7 is the same as that of
The growth rate was the same, and the properties of the resulting light-emitting devices were also at the same level.

Another example that can be easily inferred is ZnBe.

ZnS was used as a growth substrate, and Zn5y was grown on it.
It is also possible to manufacture a light emitting device using a Pn junction formed of layers set-y (0≦y≦1).

〔Effect of the invention〕

As explained above, according to the present invention, n-type Zn5ySe
ty (0≦y≦1) and P-type znsysel-y (
0≦y≦1) In the manufacturing method of a semiconductor light emitting device exhibiting blue light emission using a P-n junction formed by After reaction and aging, excess components are removed by distillation, and an organic gold M vapor phase pyrolysis method (MOO
The n-type or P-type Zn5ySθ1
By forming the -y layer, it has become possible to stably produce semiconductor devices that emit blue light. The present invention
We believe that this will greatly contribute to the production of semiconductor devices that emit blue light and the spread of various devices using them.

[Brief explanation of drawings]

Figure 1 shows the vapor pressure-temperature characteristics of (OH3)zZn-8s(aha)2. 1... Temperature 2... Vapor pressure 5.
...Adduct 4 ・--Be(OHI)2 5=
-Zn(OH3)z Figure 2 shows the MO used in the present invention.
Schematic diagram of OVD device 6... Quartz glass reaction tube 7...
Graphite susceptor with 810 coating 8... Substrate 9... High frequency heating furnace or infrared furnace or resistance heating furnace 10... Thermocouple 11... Exhaust System 12... Waste gas treatment system 13.14... Valve 15.
...Bubbler 16 containing adduct...n
Bubbler 17 containing - type dopant...Cylinder 1B containing carrier gas...Cylinder 19 containing hydrogen selenide...GaX purifier 2
0... Mass flow controller 21...
・・Thermostatic chamber 22・・・・Three-way valve 23・
...Valve 24...Cylinder containing hydrogen sulfide 25...Cylinder containing gas for n-type dopant 26...Cylinder containing gas for p-type dopant Figure 5 shows the emission spectrum of a semiconductor light emitting device manufactured by the manufacturing method according to the present invention. FIG. 4 is a correlation diagram between the gas composition and the obtained crystal composition when forming the Zn5ySθ1-y layer. that's all

Claims (2)

[Claims] (1) n-type ZnS_ySe_1_-_y (0≦y≦1
) and P-type ZnS_ySe_1_-_y (0≦y≦1)
In the manufacturing method of a semiconductor light-emitting device that emits blue light using a p-n junction formed by the method, dialkylzinc and dialkylselenium are mixed in a roughly excessive amount of the lower boiling point component of both, and the mixture is reacted and aged by heating. rear,
The n-type or P-type ZnS_ySe_1_- is produced by metal organic vapor phase pyrolysis (MOCVD) using an organozinc compound, which is an adduct of dialkylzinc and dialkylselenium obtained by distilling off excess components, as a zinc source. A method for manufacturing a semiconductor light emitting device characterized by forming a _y layer. (2) The organometallic compound used as a zinc source is 0℃~
It is an adduct formed from dialkylzinc and dialkylselenium by a heat treatment including a heating reaction step at 40°C for 10 to 180 minutes, and a step of gradually increasing the temperature and aging at 30 to 80°C for 10 to 120 minutes. A method for manufacturing a semiconductor light emitting device according to claim 1, characterized in that: